The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Among coupling members are those having a lever for performing a coupling member connecting operation, a valve opening-closing operation, etc. A pipe coupling shown in Japanese Patent Application Publication No. 2005-42857, for example, has chuck members disposed between two coaxially disposed cylindrical parts. The inner cylindrical part is displaced relative to the outer cylindrical part by pivoting a lever attached to the outer cylindrical part, thereby pivoting the chuck members so as to close the front ends of the chuck members, and thus clamping and holding by the chuck members an externally threaded portion of a pipe to be connected. In a pipe coupling shown in Japanese Patent Application Publication No. H10-89575, a valve disposed in a coupling body is moved longitudinally by pivoting a lever, thereby opening and closing a flow path.
In the above-described pipe couplings having a lever, the lever is held in position by friction between the lever and a pivot shaft thereof or by friction between the lever and another member that is cam-engaged therewith. In this regard, however, the lever may pivot accidentally when the lever is hit against or caught in something, for example, and thus a relatively large force may be applied to the lever. Then, the connected pipe may be disconnected, or the valve may be opened or closed, unintentionally.